Iron Speciation and Cycling in the Eastern Tropical North Pacific

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

ABSTRACT OCE-0220959 Taking advantage of existing cruise opportunities to take place in the Eastern Tropical North Pacific, off the coast of Mexico, a number of field analytical measurements and laboratory investigations are proposed to further research into iron bioavailability and marine iron ligand chemistry. Dominant phytoplankton communities in this region, Prochlorococcus and Synechococcus, are to be studied in the context of a layered euphotic zone overlying a suboxic zone presenting distinct sub-environments having strong chemical gradients in nutrient, trace metal, oxygen and light regimes. Activities such as trace metal sampling, on-deck incubations using competitive ligand binding voltammetric techniques, deliberate iron amendment and natural ligand photochemical decomposition studies will be studied in a mechanistic and process study manner. The anticipated outcome of these investigations is increased understanding of the biogeochemistry, speciation and cycling of dissolved iron, a trace element often thought to be limiting to phytoplankton growth, in the ocean.